Cooling device for electric discharge tubes



April 1, 1958 J. c. VAN WARMERDAM 2,829,290

009mm; DEVICE FOR ELECTRIC DISCHARGE TUBES Filed March 18, 1953 INVENTOR JOABNES CORNEUS VAN WARMER AM AGENT United States Patent COOLING DEVICE FOR ELECTRIC DISCHARGE TUBES Joannes Cornelis van Warmerdam, Eindhoven, Netherlands, assignor, by mesne assignments, to North American Philips Company, Inc., New York, N. Y., a corporation of Delaware Application March 18, 1953, Serial No. 343,076

Claims priority, application Netherlands April 10, 1952 3 Claims. (Cl. 313-45) This invention relates to a cooling device for cooling, by means of a gaseous cooling medium, the cylindrical anode of an electric discharge tube which comprises a plurality of radial, cooling fins, the cooling medium being.

supplied at one of the extremities of the fins and the fins externally being either united to form a closed envelope or surrounded thereby.

The amount of heat which may be dissipated in cool" ing devices of the above-mentioned kind is limited by the temperature loss in the cooling fins, so that a large radial length of the cooling fins has in most cases no use, and furthermore by the fact that the fins must not be too long in the axial direction, since otherwise near the extremities of the cooling fins at which the cooling medium blows out, heat can no longer be dissipated to the cooling medium due to its becoming warmer and warmer. The cooling device concerned is in most cases of comparatively high weight, which frequently constitutes a disadvantage. 1

The object of the invention is to provide an improvement of cooling devices of the above-mentioned kind, by which either the dissipation of heat in a cooler of determined size is improved, or the cooling fins in the axial direction may be of greater length.

According to the invention, in a cooling device for cooling, by means of a gaseous cooling medium, the cylindrical anode of an electric discharge tube which comprises radial cooling fins, in which device the cooling medium is supplied at one of the extremities of the fins and the fins are externally either united to form a closed envelope or surrounded thereby, the cooling medium is suppliednot only at one of the extremities of the fins but also at one or more places distributed over the-length of the fins in such manner that the flows of cooling medium join. The cooling medium is preferably supplied through two co-axial tubes, of which the inner tube is provided with apertures and either constitutes the outer envelope of the cooling fins or is connected thereto. In the latter case, said envelope is likewise provided with apertures.

If additional cooling air is supplied between the fins at only one place, the apertures are provided over half or two third parts of their length, reckoned from the beginning. The amount of secondary cooling air is in this case from to of the total amount.

The above-mentioned step ensures that at the area, at which the additional cooling medium is supplied, its temperature is decreased, whilst the speed and the turbulence are increased. Said three factors contribute to an increase of the coefficient of thermal transmission over the remaining portion of the cooling fins, so that in total a greater amount of heat is dissipated than if the full amount of cooling medium were supplied at the begin 2,829,290 Patented Apr. 1, 1958 chargetube arranged therein, as shown in Fig. 1, whereas Fig. 2 gives a bottom View of the device.

in the figures, reference numeral 1 indicates the glass upper part of a discharge tube which is shown broken off. 2 indicates the copper anode which is secured by means of soldering mass 3 in a cylinder 4, likewise of copper. The cylinder 4 comprises a flange a", which is connectcdto the cooling conduits, and a plurality of cooling fins 6. The cooling flange 5 is connected to an outer tube 7 which contains an inner tube 3, said tubes jointly constituting the supply conduit for the cooling air. The cooling air substantially flows from above downwards between the cooling fins, but cooling air is also blown between the fins through apertures 9 and 10.

What I claim is:

1. In combination, an electric discharge tube having a cylindrical anode with a longitudinal axis, and a device for cooling said anode with a gaseous cooling medium; said device comprising a plurality of circumferentiallyspaced radial cooling fins mounted on said anode, an envelope member having longitudinally-spaced apertures surrounding and secured to the edges of said fins, and means coacting with said envelope member for introducing a cooling medium at one of the extremities of the fins and through the apertures in said member longitudinally spaced from said extremity to said fins, whereby the flows of the cooling medium join while passing along the fins in an axial direction thereby increasing the velocity of the cooling medium.

2. In combination, an electric discharge tube having a cylindrical anode with a longitudinal axis, and a device for cooling said anode with a gaseous cooling medium; said device comprising a plurality of longitudinally extending circumferentially spaced fins radially mounted on said anode, an inner tube having longitudinally spaced apertures in its wall and aligned with said axis and joined to and surrounding the edges of the fins, a solid outer tube concentric with and surrounding said inner tube and sealing off one end of said fins, and means associated with said tubes for introducing a cooling medium in the space between said tubes whereby the flow of cooling medium is through the apertures in said inner tube to the fins so that the flows join while passing axially along the fins and increase the velocity of the medium.

3. In combination; an electric discharge tube having a substantially cylindrical anode with a longitudinal axis, a plurality of longitudinally-extending circumferentiallyspaced fins mounted onsaid anode and defining therebetween a plurality of parallel longitudinal cooling paths communicating with said anode, an envelope member surrounding said fins and secured to the edges thereof remote from the anode to close oil the cooling paths, said envelope having a plurality of axially-spaced annular apertures therein enabling access to the cooling paths, and means for introducing a cooling medium through a plurality of said apertures into said cooling paths at axiallyspaced positions and withdrawing said cooling medium from one extremity of said fins, whereby the flows of the cooling medium join along the cooling paths thereby increasing the velocity of the cooling medium.

References Cited in the file of this patent UNITED STATES PATENTS 1,874,679 Willoughby Aug. 30, 1932 2,045,659 Lindenblad June 30, 1936 2,362,911 Litton Nov. 14, 1944 2,513,920 De Walt July 4, 1950 FOREIGN PATENTS 514,651 Great Britain Nov. 14, 1939 564,357 Great Britain Sept. 25, 1944 

